The Ultimate List of Brain Weights for Animals

The brain size can differ greatly between animals including among species of the same animal.

We wanted here to list the brain weights of many common/familiar animals on the planet. Other such lists on the internet are not that big and probably missing many important animals.

This reference article will be helpful for someone writing a relevant article, comparing the brain weights of animals, comparing the intelligence of animals or just learning about brain sizes in general.

Here is the data in both metric and imperial units:

Please note the following about the data in the table:

• For each animal species, we tried to use the data of male when possible
• If there are more than one species of the animal, we simply used the most popular one
• We included the brain-body mass ratio because it could be an indicator of the animal’s intelligence

The brain sizes (in grams) were sourced from datasets of some academic journals, which are referenced below. And the brain-body mass ratio was calculated based on the body weight available in the data.

To conclude, we have listed the brain weights and ratios of many common animals. The list is exclusively about vertebrates which includes mammals, birds, fish, reptiles and amphibians. And the measurements are both in metric (g) and imperial units (oz).

From the elephant to crocodile to dolphin to frog, you can find and compare the brain size of over 160 different animals across several animal classes.

This is one of the shortest articles we have published so far since it merely lists some animal’s brain sizes. But of course, compiling all these numbers took quite some time to do.

Hope the information was helpful for you.

Please let us know if you want the brain data of any more animals to be included in the list.

Lastly, be sure to check out our article about animals with largest & smallest brain size, you will probably learn something new and interesting on that topic.

Reference

• Burger J.R., George M.A., Leadbetter C., Shaikh F. (2019). The allometry of brain size in mammals. Journal of Mammalogy, 100(2), 276-283. https://doi.org/10.1093/jmammal/gyz043
• Stark, G., Pincheira-Donoso, D (2022). The Evolution of Brain Size in Ectothermic Tetrapods: Large Brain Mass Trades-Off with Lifespan in Reptiles. Evol Biol, 49, 180–188. https://doi.org/10.1007/s11692-022-09562-4
• Jungwirth, A. (2022). Data for: The costs and benefits of larger brains in fishes. Dryad. https://doi.org/10.5061/dryad.sxksn035q
• Song, Z. (2023). Data from: Why do endothermic vertebrates have bigger brains than ectothermic ones. Dryad. https://doi.org/10.5061/dryad.hqbzkh1mq